man/systemctl.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU General Public License as published by
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  13   (at your option) any later version.
  14
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  18   General Public License for more details.
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  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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  23
  24 <refentry id="systemctl">
  25
  26         <refentryinfo>
  27                 <title>systemctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemctl</refname>
  47                 <refpurpose>Control the systemd system and service manager</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>systemctl</command> may be used to
  60                 introspect and control the state of the
  61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  62                 system and service manager.</para>
  63         </refsect1>
  64
  65         <refsect1>
  66                 <title>Options</title>
  67
  68                 <para>The following options are understood:</para>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><option>--help</option></term>
  73                                 <term><option>-h</option></term>
  74
  75                                 <listitem><para>Prints a short help
  76                                 text and exits.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>--version</option></term>
  81
  82                                 <listitem><para>Prints a short version
  83                                 string and exits.</para></listitem>
  84                         </varlistentry>
  85
  86                         <varlistentry>
  87                                 <term><option>--type=</option></term>
  88                                 <term><option>-t</option></term>
  89
  90                                 <listitem><para>When listing units,
  91                                 limit display to certain unit
  92                                 types. If not specified units of all
  93                                 types will be shown. The argument
  94                                 should be a unit type name such as
  95                                 <option>service</option>,
  96                                 <option>socket</option> and
  97                                 similar.</para></listitem>
  98                         </varlistentry>
  99
 100                         <varlistentry>
 101                                 <term><option>--property=</option></term>
 102                                 <term><option>-p</option></term>
 103
 104                                 <listitem><para>When showing
 105                                 unit/job/manager information, limit
 106                                 display to certain properties as
 107                                 specified as argument. If not
 108                                 specified all set properties are
 109                                 shown. The argument should be a
 110                                 property name, such as
 111                                 <literal>MainPID</literal>. If
 112                                 specified more than once all
 113                                 properties with the specified names
 114                                 are shown.</para></listitem>
 115                         </varlistentry>
 116
 117                         <varlistentry>
 118                                 <term><option>--all</option></term>
 119                                 <term><option>-a</option></term>
 120
 121                                 <listitem><para>When listing units,
 122                                 show all units, regardless of their
 123                                 state, including inactive units. When
 124                                 showing unit/job/manager information,
 125                                 show all properties regardless whether
 126                                 they are set or not.</para></listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><option>--failed</option></term>
 131
 132                                 <listitem><para>When listing units,
 133                                 show only failed units. Do not confuse
 134                                 with
 135                                 <option>--fail</option>.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><option>--full</option></term>
 140
 141                                 <listitem><para>Do not ellipsize unit
 142                                 names and truncate unit descriptions
 143                                 in the output of
 144                                 <command>list-units</command> and
 145                                 <command>list-jobs</command>.</para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><option>--fail</option></term>
 150
 151                                 <listitem><para>If the requested
 152                                 operation conflicts with a pending
 153                                 unfinished job, fail the command. If
 154                                 this is not specified the requested
 155                                 operation will replace the pending job,
 156                                 if necessary. Do not confuse
 157                                 with
 158                                 <option>--failed</option>.</para></listitem>
 159                         </varlistentry>
 160
 161                         <varlistentry>
 162                                 <term><option>--ignore-dependencies</option></term>
 163
 164                                 <listitem><para>When enqueuing a new
 165                                 job ignore all its dependencies and
 166                                 execute it immediately. If passed no
 167                                 required units of the unit passed will
 168                                 be pulled in, and no ordering
 169                                 dependencies will be honoured. This is
 170                                 mostly a debugging and rescue tool for
 171                                 the administrator and should not be
 172                                 used by
 173                                 applications.</para></listitem>
 174                         </varlistentry>
 175
 176                         <varlistentry>
 177                                 <term><option>--quiet</option></term>
 178                                 <term><option>-q</option></term>
 179
 180                                 <listitem><para>Suppress output to
 181                                 STDOUT in
 182                                 <command>snapshot</command>,
 183                                 <command>is-active</command>,
 184                                 <command>enable</command> and
 185                                 <command>disable</command>.</para></listitem>
 186                         </varlistentry>
 187
 188                         <varlistentry>
 189                                 <term><option>--no-block</option></term>
 190
 191                                 <listitem><para>Do not synchronously wait for
 192                                 the requested operation to finish. If this is
 193                                 not specified the job will be verified,
 194                                 enqueued and <command>systemctl</command> will
 195                                 wait until it is completed. By passing this
 196                                 argument it is only verified and
 197                                 enqueued.</para></listitem> </varlistentry>
 198
 199                         <varlistentry>
 200                                 <term><option>--no-pager</option></term>
 201
 202                                 <listitem><para>Do not pipe output into a
 203                                 pager.</para></listitem>
 204                         </varlistentry>
 205
 206                         <varlistentry>
 207                                 <term><option>--system</option></term>
 208
 209                                 <listitem><para>Talk to the systemd
 210                                 system manager. (Default)</para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>--user</option></term>
 215
 216                                 <listitem><para>Talk to the systemd
 217                                 manager of the calling user.</para></listitem>
 218                         </varlistentry>
 219
 220                         <varlistentry>
 221                                 <term><option>--order</option></term>
 222                                 <term><option>--require</option></term>
 223
 224                                 <listitem><para>When used in
 225                                 conjunction with the
 226                                 <command>dot</command> command (see
 227                                 below), selects which dependencies are
 228                                 shown in the dependency graph. If
 229                                 <option>--order</option> is passed
 230                                 only dependencies of type
 231                                 <varname>After=</varname> or
 232                                 <varname>Before=</varname> are
 233                                 shown. If <option>--require</option>
 234                                 is passed only dependencies of type
 235                                 <varname>Requires=</varname>,
 236                                 <varname>RequiresOverridable=</varname>,
 237                                 <varname>Requisite=</varname>,
 238                                 <varname>RequisiteOverridable=</varname>,
 239                                 <varname>Wants=</varname> and
 240                                 <varname>Conflicts=</varname> are
 241                                 shown. If neither is passed, shows
 242                                 dependencies of all these
 243                                 types.</para></listitem>
 244                         </varlistentry>
 245
 246                         <varlistentry>
 247                                 <term><option>--no-wall</option></term>
 248
 249                                 <listitem><para>Don't send wall
 250                                 message before
 251                                 halt, power-off, reboot.</para></listitem>
 252                         </varlistentry>
 253
 254                         <varlistentry>
 255                                 <term><option>--global</option></term>
 256
 257                                 <listitem><para>When used with
 258                                 <command>enable</command> and
 259                                 <command>disable</command>, operate on the
 260                                 global user configuration
 261                                 directory, thus enabling or disabling
 262                                 a unit file globally for all future
 263                                 logins of all users.</para></listitem>
 264                         </varlistentry>
 265
 266                         <varlistentry>
 267                                 <term><option>--no-reload</option></term>
 268
 269                                 <listitem><para>When used with
 270                                 <command>enable</command> and
 271                                 <command>disable</command>, do not
 272                                 implicitly reload daemon configuration
 273                                 after executing the
 274                                 changes.</para></listitem>
 275                         </varlistentry>
 276
 277                         <varlistentry>
 278                                 <term><option>--no-ask-password</option></term>
 279
 280                                 <listitem><para>When used with
 281                                 <command>start</command> and related
 282                                 commands, disables asking for
 283                                 passwords. Background services may
 284                                 require input of a password or
 285                                 passphrase string, for example to
 286                                 unlock system hard disks or
 287                                 cryptographic certificates. Unless
 288                                 this option is specified and the
 289                                 command is invoked from a terminal
 290                                 <command>systemctl</command> will
 291                                 query the user on the terminal for the
 292                                 necessary secrets. Use this option to
 293                                 switch this behavior off. In this
 294                                 case the password must be supplied by
 295                                 some other means (for example
 296                                 graphical password agents) or the
 297                                 service might fail.</para></listitem>
 298                         </varlistentry>
 299
 300                         <varlistentry>
 301                                 <term><option>--kill-mode=</option></term>
 302
 303                                 <listitem><para>When used with
 304                                 <command>kill</command>, choose the
 305                                 mode how to kill the selected
 306                                 processes. Must be one of
 307                                 <option>control-group</option>,
 308                                 <option>process-group</option> or
 309                                 <option>process</option> to select
 310                                 whether to kill the entire control
 311                                 group, the process group or only the
 312                                 selected process itself. If omitted
 313                                 defaults to
 314                                 <option>control-group</option> if
 315                                 <option>--kill-who=all</option> is
 316                                 set, or <option>process</option>
 317                                 otherwise. You probably never need to
 318                                 use this switch.</para></listitem>
 319                         </varlistentry>
 320
 321                         <varlistentry>
 322                                 <term><option>--kill-who=</option></term>
 323
 324                                 <listitem><para>When used with
 325                                 <command>kill</command>, choose which
 326                                 processes to kill. Must be one of
 327                                 <option>main</option>,
 328                                 <option>control</option> or
 329                                 <option>all</option> to select whether
 330                                 to kill only the main process of the
 331                                 unit, the control process or all
 332                                 processes of the unit. If omitted
 333                                 defaults to
 334                                 <option>all</option>.</para></listitem>
 335                         </varlistentry>
 336
 337                         <varlistentry>
 338                                 <term><option>--signal=</option></term>
 339                                 <term><option>-s</option></term>
 340
 341                                 <listitem><para>When used with
 342                                 <command>kill</command>, choose which
 343                                 signal to send to selected
 344                                 processes. Must be one of the well
 345                                 known signal specifiers such as
 346                                 SIGTERM, SIGINT or SIGSTOP. If
 347                                 omitted defaults to
 348                                 <option>SIGTERM</option>.</para></listitem>
 349                         </varlistentry>
 350
 351                         <varlistentry>
 352                                 <term><option>--force</option></term>
 353                                 <term><option>-f</option></term>
 354
 355                                 <listitem><para>When used with
 356                                 <command>enable</command>, override any
 357                                 existing conflicting
 358                                 symlinks.</para></listitem>
 359
 360                                 <listitem><para>When used with
 361                                 <command>halt</command>,
 362                                 <command>poweroff</command>,
 363                                 <command>reboot</command> or
 364                                 <command>kexec</command> execute
 365                                 selected operation without shutting
 366                                 down all units. However, all processes
 367                                 will be killed forcibly and all file
 368                                 systems are unmounted or remounted
 369                                 read-only. This is hence a drastic but
 370                                 relatively safe option to request an
 371                                 immediate reboot.</para></listitem>
 372                         </varlistentry>
 373
 374                         <varlistentry>
 375                                 <term><option>--defaults</option></term>
 376
 377                                 <listitem><para>When used with
 378                                 <command>disable</command>, ensures
 379                                 that only the symlinks created by
 380                                 <command>enable</command> are removed,
 381                                 not all symlinks pointing to the unit
 382                                 file that shall be
 383                                 disabled.</para></listitem>
 384                         </varlistentry>
 385
 386                         <varlistentry>
 387                                 <term><option>-H</option></term>
 388                                 <term><option>--host</option></term>
 389
 390                                 <listitem><para>Execute operation
 391                                 remotely. Specifiy a hostname, or
 392                                 username and hostname seperated by @,
 393                                 to connect to. This will use SSH to
 394                                 talk to the remote systemd
 395                                 instance.</para></listitem>
 396                         </varlistentry>
 397
 398                         <varlistentry>
 399                                 <term><option>-P</option></term>
 400                                 <term><option>--privileged</option></term>
 401
 402                                 <listitem><para>Acquire privileges via
 403                                 PolicyKit before executing the
 404                                 operation.</para></listitem>
 405                         </varlistentry>
 406                 </variablelist>
 407
 408                 <para>The following commands are understood:</para>
 409
 410                 <variablelist>
 411                         <varlistentry>
 412                                 <term><command>list-units</command></term>
 413
 414                                 <listitem><para>List known units.</para></listitem>
 415                         </varlistentry>
 416                         <varlistentry>
 417                                 <term><command>start [NAME...]</command></term>
 418
 419                                 <listitem><para>Start (activate) one
 420                                 or more units specified on the command
 421                                 line.</para></listitem>
 422                         </varlistentry>
 423                         <varlistentry>
 424                                 <term><command>stop [NAME...]</command></term>
 425
 426                                 <listitem><para>Stop (deactivate) one
 427                                 or more units specified on the command
 428                                 line.</para></listitem>
 429                         </varlistentry>
 430                         <varlistentry>
 431                                 <term><command>reload [NAME...]</command></term>
 432
 433                                 <listitem><para>Asks all units listed
 434                                 on the command line to reload their
 435                                 configuration. Note that this will
 436                                 reload the service-specific
 437                                 configuration, not the unit
 438                                 configuration file of systemd. If you
 439                                 want systemd to reload the
 440                                 configuration file of a unit use the
 441                                 <command>daemon-reload</command>
 442                                 command. In other words: for the
 443                                 example case of Apache, this will
 444                                 reload Apache's
 445                                 <filename>httpd.conf</filename> in the
 446                                 web server, not the
 447                                 <filename>apache.service</filename>
 448                                 systemd unit file. </para>
 449
 450                                 <para>This command should not be
 451                                 confused with the
 452                                 <command>daemon-reload</command> or
 453                                 <command>load</command>
 454                                 commands.</para></listitem>
 455
 456                         </varlistentry>
 457                         <varlistentry>
 458                                 <term><command>restart [NAME...]</command></term>
 459
 460                                 <listitem><para>Restart one or more
 461                                 units specified on the command
 462                                 line. If the units are not running yet
 463                                 they will be
 464                                 started.</para></listitem>
 465                         </varlistentry>
 466                         <varlistentry>
 467                                 <term><command>try-restart [NAME...]</command></term>
 468
 469                                 <listitem><para>Restart one or more
 470                                 units specified on the command
 471                                 line. If the units are not running yet
 472                                 the operation will
 473                                 fail. Note that for compatibility
 474                                 with Red Hat init scripts
 475                                 <command>condrestart</command> is
 476                                 equivalent to this command.</para></listitem>
 477                         </varlistentry>
 478                         <varlistentry>
 479                                 <term><command>reload-or-restart [NAME...]</command></term>
 480
 481                                 <listitem><para>Reload one or more
 482                                 units if they support it. If not,
 483                                 restart them instead. If the units
 484                                 are not running yet they will be
 485                                 started.</para></listitem>
 486                         </varlistentry>
 487                         <varlistentry>
 488                                 <term><command>reload-or-try-restart [NAME...]</command></term>
 489
 490                                 <listitem><para>Reload one or more
 491                                 units if they support it. If not,
 492                                 restart them instead. If the units
 493                                 are not running yet the operation
 494                                 will fail. Note that for
 495                                 compatibility with SysV init scripts
 496                                 <command>force-reload</command> is
 497                                 equivalent to this command.</para></listitem>
 498                         </varlistentry>
 499                         <varlistentry>
 500                                 <term><command>isolate [NAME]</command></term>
 501
 502                                 <listitem><para>Start the unit
 503                                 specified on the command line and its
 504                                 dependencies and stop all others.</para>
 505
 506                                 <para>This is similar to changing the
 507                                 runlevel in a traditional init system. The
 508                                 <command>isolate</command> command will
 509                                 immediately stop processes that are not
 510                                 enabled in the new unit, possibly including
 511                                 the graphical environment or terminal you
 512                                 are currently using.</para>
 513
 514                                 <para>Note that this works only on units
 515                                 where <option>AllowIsolate=</option> is
 516                                 enabled. See
 517                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 518                                 for details.</para></listitem>
 519                         </varlistentry>
 520                         <varlistentry>
 521                                 <term><command>kill [NAME...]</command></term>
 522
 523                                 <listitem><para>Send a signal to one
 524                                 or more processes of the unit. Use
 525                                 <option>--kill-who=</option> to select
 526                                 which process to kill. Use
 527                                 <option>--kill-mode=</option> to
 528                                 select the kill mode and
 529                                 <option>--signal=</option> to select
 530                                 the signal to send.</para></listitem>
 531                         </varlistentry>
 532                         <varlistentry>
 533                                 <term><command>is-active [NAME...]</command></term>
 534
 535                                 <listitem><para>Check whether any of
 536                                 the specified units are active
 537                                 (i.e. running). Returns an exit code
 538                                 0 if at least one is active, non-zero
 539                                 otherwise. Unless
 540                                 <option>--quiet</option> is specified
 541                                 this will also print the current unit
 542                                 state to STDOUT.</para></listitem>
 543                         </varlistentry>
 544                         <varlistentry>
 545                                 <term><command>status [NAME...|PID...]</command></term>
 546
 547                                 <listitem><para>Show terse runtime
 548                                 status information about one or more
 549                                 units. This function is intended to
 550                                 generate human-readable output. If you
 551                                 are looking for computer-parsable
 552                                 output, use <command>show</command>
 553                                 instead. If a PID is passed
 554                                 information about the unit the process
 555                                 of the PID belongs to is
 556                                 shown.</para></listitem>
 557                         </varlistentry>
 558                         <varlistentry>
 559                                 <term><command>show [NAME...|JOB...]</command></term>
 560
 561                                 <listitem><para>Show properties of one
 562                                 or more units, jobs or the manager
 563                                 itself. If no argument is specified
 564                                 properties of the manager will be
 565                                 shown. If a unit name is specified
 566                                 properties of the unit is shown, and
 567                                 if a job id is specified properties of
 568                                 the job is shown. By default, empty
 569                                 properties are suppressed. Use
 570                                 <option>--all</option> to show those
 571                                 too. To select specific properties to
 572                                 show use
 573                                 <option>--property=</option>. This
 574                                 command is intended to be used
 575                                 whenever computer-parsable output is
 576                                 required. Use
 577                                 <command>status</command> if you are
 578                                 looking for formatted human-readable
 579                                 output.</para></listitem>
 580                         </varlistentry>
 581
 582                         <varlistentry>
 583                                 <term><command>reset-failed [NAME...]</command></term>
 584
 585                                 <listitem><para>Reset the
 586                                 '<literal>failed</literal>' state of the
 587                                 specified units, or if no unit name is
 588                                 passed of all units. When a unit fails
 589                                 in some way (i.e. process exiting with
 590                                 non-zero error code, terminating
 591                                 abnormally or timing out) it will
 592                                 automatically enter the
 593                                 '<literal>failed</literal>' state and
 594                                 its exit code and status is recorded
 595                                 for introspection by the administrator
 596                                 until the service is restarted or
 597                                 reset with this
 598                                 command.</para></listitem>
 599                         </varlistentry>
 600
 601                         <varlistentry>
 602                                 <term><command>enable [NAME...]</command></term>
 603
 604                                 <listitem><para>Enable one or more
 605                                 unit files, as specified on the
 606                                 command line. This will create a
 607                                 number of symlinks as encoded in the
 608                                 <literal>[Install]</literal> sections
 609                                 of the unit files. After the symlinks
 610                                 have been created the systemd
 611                                 configuration is reloaded (in a way
 612                                 that is equivalent to
 613                                 <command>daemon-reload</command>) to
 614                                 ensure the changes are taken into
 615                                 account immediately. Note that this
 616                                 does not have the effect that any of
 617                                 the units enabled are also started at
 618                                 the same time. If this is desired a
 619                                 separate <command>start</command>
 620                                 command must be invoked for the
 621                                 unit.</para>
 622
 623                                 <para>This command will
 624                                 print the actions executed. This
 625                                 output may be suppressed by passing
 626                                 <option>--quiet</option>.</para>
 627
 628                                 <para>Note that this operation creates
 629                                 only the suggested symlinks for the
 630                                 units. While this command is the
 631                                 recommended way to manipulate the unit
 632                                 configuration directory, the
 633                                 administrator is free to make
 634                                 additional changes manually, by
 635                                 placing or removing symlinks in the
 636                                 directory. This is particularly useful
 637                                 to create configurations that deviate
 638                                 from the suggested default
 639                                 installation. In this case the
 640                                 administrator must make sure to invoke
 641                                 <command>daemon-reload</command>
 642                                 manually as necessary, to ensure his
 643                                 changes are taken into account.</para>
 644
 645                                 <para>Enabling units should not be
 646                                 confused with starting (activating)
 647                                 units, as done by the
 648                                 <command>start</command>
 649                                 command. Enabling and starting units
 650                                 is orthogonal: units may be enabled
 651                                 without being started and started
 652                                 without being enabled. Enabling simply
 653                                 hooks the unit into various suggested
 654                                 places (for example, so that the unit
 655                                 is automatically started on boot or
 656                                 when a particular kind of hardware is
 657                                 plugged in). Starting actually spawns
 658                                 the daemon process (in case of service
 659                                 units), or binds the socket (in case
 660                                 of socket units), and so
 661                                 on.</para>
 662
 663                                 <para>Depending on whether
 664                                 <option>--system</option>,
 665                                 <option>--user</option> or
 666                                 <option>--global</option> is specified
 667                                 this enables the unit for the system,
 668                                 for the calling user only
 669                                 or for all future logins of all
 670                                 users. Note that in the latter case no
 671                                 systemd daemon configuration is
 672                                 reloaded.</para>
 673                                 </listitem>
 674                         </varlistentry>
 675
 676                         <varlistentry>
 677                                 <term><command>disable [NAME...]</command></term>
 678
 679                                 <listitem><para>Disables one or more
 680                                 units. This removes all symlinks to
 681                                 the specified unit files from the unit
 682                                 configuration directory, and hence
 683                                 undoes the changes made by
 684                                 <command>enable</command>. Note
 685                                 however that this by default removes
 686                                 all symlinks to the unit files
 687                                 (i.e. including manual additions), not
 688                                 just those actually created by
 689                                 <command>enable</command>. If only the
 690                                 symlinks that are suggested by default
 691                                 shall be removed, pass
 692                                 <option>--defaults</option>. This
 693                                 implicitly reloads the systemd daemon
 694                                 configuration after completing the
 695                                 disabling of the units. Note that this
 696                                 command does not implicitly stop the
 697                                 units that is being disabled. If this
 698                                 is desired an additional
 699                                 <command>stop</command>command should
 700                                 be executed afterwards.</para>
 701
 702                                 <para>This command will print the
 703                                 actions executed. This output may be
 704                                 suppressed by passing
 705                                 <option>--quiet</option>.</para>
 706                                 </listitem>
 707
 708                                 <para>This command honors
 709                                 <option>--system</option>,
 710                                 <option>--user</option>,
 711                                 <option>--global</option> in a similar
 712                                 way as
 713                                 <command>enable</command>.</para>
 714                         </varlistentry>
 715
 716                         <varlistentry>
 717                                 <term><command>is-enabled [NAME...]</command></term>
 718
 719                                 <listitem><para>Checks whether any of
 720                                 the specified unit files is enabled
 721                                 (as with
 722                                 <command>enable</command>). Returns an
 723                                 exit code of 0 if at least one is
 724                                 enabled, non-zero
 725                                 otherwise.</para></listitem>
 726                         </varlistentry>
 727
 728                         <varlistentry>
 729                                 <term><command>load [NAME...]</command></term>
 730
 731                                 <listitem><para>Load one or more units
 732                                 specified on the command line. This
 733                                 will simply load their configuration
 734                                 from disk, but not start them. To
 735                                 start them you need to use the
 736                                 <command>start</command> command which
 737                                 will implicitly load a unit that has
 738                                 not been loaded yet. Note that systemd
 739                                 garbage collects loaded units that are
 740                                 not active or referenced by an active
 741                                 unit. This means that units loaded
 742                                 this way will usually not stay loaded
 743                                 for long. Also note that this command
 744                                 cannot be used to reload unit
 745                                 configuration. Use the
 746                                 <command>daemon-reload</command>
 747                                 command for that. All in all, this
 748                                 command is of little use except for
 749                                 debugging.</para>
 750                                 <para>This command should not be
 751                                 confused with the
 752                                 <command>daemon-reload</command> or
 753                                 <command>reload</command>
 754                                 commands.</para></listitem>
 755                         </varlistentry>
 756                         <varlistentry>
 757                                 <term><command>list-jobs</command></term>
 758
 759                                 <listitem><para>List jobs that are in progress.</para></listitem>
 760                         </varlistentry>
 761                         <varlistentry>
 762                                 <term><command>cancel [JOB...]</command></term>
 763
 764                                 <listitem><para>Cancel one or more
 765                                 jobs specified on the command line by
 766                                 their numeric job
 767                                 IDs. If no job id is specified, cancel all pending jobs.</para></listitem>
 768                         </varlistentry>
 769                         <varlistentry>
 770                                 <term><command>monitor</command></term>
 771
 772                                 <listitem><para>Monitor unit/job
 773                                 changes. This is mostly useful for
 774                                 debugging purposes and prints a line
 775                                 each time systemd loads or unloads a
 776                                 unit configuration file, or a unit
 777                                 property changes.</para></listitem>
 778                         </varlistentry>
 779                         <varlistentry>
 780                                 <term><command>dump</command></term>
 781
 782                                 <listitem><para>Dump server
 783                                 status. This will output a (usually
 784                                 very long) human readable manager
 785                                 status dump. Its format is subject to
 786                                 change without notice and should not
 787                                 be parsed by
 788                                 applications.</para></listitem>
 789                         </varlistentry>
 790                         <varlistentry>
 791                                 <term><command>dot</command></term>
 792
 793                                 <listitem><para>Generate textual
 794                                 dependency graph description in dot
 795                                 format for further processing with the
 796                                 GraphViz
 797                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 798                                 tool. Use a command line like
 799                                 <command>systemctl dot | dot -Tsvg >
 800                                 systemd.svg</command> to generate a
 801                                 graphical dependency tree. Unless
 802                                 <option>--order</option> or
 803                                 <option>--require</option> is passed
 804                                 the generated graph will show both
 805                                 ordering and requirement
 806                                 dependencies.</para></listitem>
 807                         </varlistentry>
 808                         <varlistentry>
 809                                 <term><command>snapshot [NAME]</command></term>
 810
 811                                 <listitem><para>Create a snapshot. If
 812                                 a snapshot name is specified, the new
 813                                 snapshot will be named after it. If
 814                                 none is specified an automatic
 815                                 snapshot name is generated. In either
 816                                 case, the snapshot name used is
 817                                 printed to STDOUT, unless
 818                                 <option>--quiet</option> is
 819                                 specified.</para>
 820
 821                                 <para>A snapshot refers to a saved
 822                                 state of the systemd manager. It is
 823                                 implemented itself as a unit that is
 824                                 generated dynamically with this
 825                                 command and has dependencies on all
 826                                 units active at the time. At a later
 827                                 time the user may return to this state
 828                                 by using the
 829                                 <command>isolate</command> command on
 830                                 the snapshot unit.</para></listitem>
 831
 832                                 <para>Snapshots are only useful for
 833                                 saving and restoring which units are
 834                                 running or are stopped, they do not
 835                                 save/restore any other
 836                                 state. Snapshots are dynamic and lost
 837                                 on reboot.</para>
 838                         </varlistentry>
 839                         <varlistentry>
 840                                 <term><command>delete [NAME...]</command></term>
 841
 842                                 <listitem><para>Remove a snapshot
 843                                 previously created with
 844                                 <command>snapshot</command>.</para></listitem>
 845                         </varlistentry>
 846                         <varlistentry>
 847                                 <term><command>daemon-reload</command></term>
 848
 849                                 <listitem><para>Reload systemd manager
 850                                 configuration. This will reload all
 851                                 unit files and recreate the entire
 852                                 dependency tree. While the daemon is
 853                                 reloaded, all sockets systemd listens
 854                                 on on behalf of user configuration will
 855                                 stay accessible.</para> <para>This
 856                                 command should not be confused with
 857                                 the <command>load</command> or
 858                                 <command>reload</command>
 859                                 commands.</para></listitem>
 860                         </varlistentry>
 861                         <varlistentry>
 862                                 <term><command>daemon-reexec</command></term>
 863
 864                                 <listitem><para>Reexecute the systemd
 865                                 manager. This will serialize the
 866                                 manager state, reexecute the process
 867                                 and deserialize the state again. This
 868                                 command is of little use except for
 869                                 debugging and package
 870                                 upgrades. Sometimes it might be
 871                                 helpful as a heavy-weight
 872                                 <command>daemon-reload</command>. While
 873                                 the daemon is reexecuted all sockets
 874                                 systemd listens on on behalf of user
 875                                 configuration will stay
 876                                 accessible.</para></listitem>
 877                         </varlistentry>
 878                         <varlistentry>
 879                                 <term><command>show-environment</command></term>
 880
 881                                 <listitem><para>Dump the systemd
 882                                 manager environment block. The
 883                                 environment block will be dumped in
 884                                 straight-forward form suitable for
 885                                 sourcing into a shell script. This
 886                                 environment block will be passed to
 887                                 all processes the manager
 888                                 spawns.</para></listitem>
 889                         </varlistentry>
 890                         <varlistentry>
 891                                 <term><command>set-environment [NAME=VALUE...]</command></term>
 892
 893                                 <listitem><para>Set one or more
 894                                 systemd manager environment variables,
 895                                 as specified on the command
 896                                 line.</para></listitem>
 897                         </varlistentry>
 898                         <varlistentry>
 899                                 <term><command>unset-environment [NAME...]</command></term>
 900
 901                                 <listitem><para>Unset one or more
 902                                 systemd manager environment
 903                                 variables. If only a variable name is
 904                                 specified it will be removed
 905                                 regardless of its value. If a variable
 906                                 and a value are specified the variable
 907                                 is only removed if it has the
 908                                 specified value.</para></listitem>
 909                         </varlistentry>
 910                         <varlistentry>
 911                                 <term><command>default</command></term>
 912
 913                                 <listitem><para>Enter default
 914                                 mode. This is mostly equivalent to
 915                                 <command>start
 916                                 default.target</command>.</para></listitem>
 917                         </varlistentry>
 918                         <varlistentry>
 919                                 <term><command>rescue</command></term>
 920
 921                                 <listitem><para>Enter rescue
 922                                 mode. This is mostly equivalent to
 923                                 <command>isolate
 924                                 rescue.target</command> but also
 925                                 prints a wall message to all
 926                                 users.</para></listitem>
 927                         </varlistentry>
 928                         <varlistentry>
 929                                 <term><command>emergency</command></term>
 930
 931                                 <listitem><para>Enter emergency
 932                                 mode. This is mostly equivalent to
 933                                 <command>isolate
 934                                 emergency.target</command> but also
 935                                 prints a wall message to all
 936                                 users.</para></listitem>
 937                         </varlistentry>
 938                         <varlistentry>
 939                                 <term><command>halt</command></term>
 940
 941                                 <listitem><para>Shut down and halt the
 942                                 system. This is mostly equivalent to
 943                                 <command>start halt.target</command>
 944                                 but also prints a wall message to all
 945                                 users.  If
 946                                 combined with <option>--force</option>
 947                                 shutdown of all running services is
 948                                 skipped, however all processes are killed
 949                                 and all file systems are unmounted or
 950                                 mounted read-only, immediately
 951                                 followed by the
 952                                 system halt.</para></listitem>
 953                         </varlistentry>
 954                         <varlistentry>
 955                                 <term><command>poweroff</command></term>
 956
 957                                 <listitem><para>Shut down and
 958                                 power-off the system. This is mostly
 959                                 equivalent to <command>start
 960                                 poweroff.target</command> but also
 961                                 prints a wall message to all
 962                                 users. If
 963                                 combined with <option>--force</option>
 964                                 shutdown of all running services is
 965                                 skipped, however all processes are killed
 966                                 and all file systems are unmounted or
 967                                 mounted read-only, immediately
 968                                 followed by the
 969                                 powering off.</para></listitem>
 970                         </varlistentry>
 971                         <varlistentry>
 972                                 <term><command>reboot</command></term>
 973
 974                                 <listitem><para>Shut down and
 975                                 reboot the system. This is mostly
 976                                 equivalent to <command>start
 977                                 reboot.target</command> but also
 978                                 prints a wall message to all
 979                                 users. If
 980                                 combined with <option>--force</option>
 981                                 shutdown of all running services is
 982                                 skipped, however all processes are killed
 983                                 and all file systems are unmounted or
 984                                 mounted read-only, immediately
 985                                 followed by the
 986                                 reboot.</para></listitem>
 987                         </varlistentry>
 988                         <varlistentry>
 989                                 <term><command>kexec</command></term>
 990
 991                                 <listitem><para>Shut down and reboot
 992                                 the system via kexec. This is mostly
 993                                 equivalent to <command>start
 994                                 kexec.target</command> but also prints
 995                                 a wall message to all users. If
 996                                 combined with <option>--force</option>
 997                                 shutdown of all running services is
 998                                 skipped, however all processes are killed
 999                                 and all file systems are unmounted or
1000                                 mounted read-only, immediately
1001                                 followed by the
1002                                 reboot.</para></listitem>
1003                         </varlistentry>
1004                         <varlistentry>
1005                                 <term><command>exit</command></term>
1006
1007                                 <listitem><para>Ask the systemd
1008                                 manager to quit. This is only
1009                                 supported for user service managers
1010                                 (i.e. in conjunction with the
1011                                 <option>--user</option> option) and
1012                                 will fail otherwise.</para></listitem>
1013                         </varlistentry>
1014                 </variablelist>
1015
1016         </refsect1>
1017
1018         <refsect1>
1019                 <title>Exit status</title>
1020
1021                 <para>On success 0 is returned, a non-zero failure
1022                 code otherwise.</para>
1023         </refsect1>
1024
1025         <refsect1>
1026                 <title>See Also</title>
1027                 <para>
1028                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1029                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1030                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1031                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1032                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1033                 </para>
1034         </refsect1>
1035
1036 </refentry>